Weighing Indicator & Load Cell

"weighing indicator"

Please describe this device.

The simple answer to both questions is probally yes.

Most weighing indicators can be programmed for a tare weight, you could also possibly span the indicator so that the 4-20ma output will work over the 1 ton range that you want to use.

Also how accurate does the range have to be? The reason that I ask this is that I presume that you have not used load cell summing junction boxes, and you can get a problem when using 4 load cells, the problem is that if they are not set up correctly one load cell can work against the others, its a bit like a 4 legged chair with one leg shorter than the rest. I prefer to use 3 load cells where ever possible, because you wont get that rocking action

Cheers

Joe

thank you nick name and also another friends,

i will contact you for the detail..

Hi friend, 1, 5t weight of your conveyor is the tare weight of the equipment once we do the tare then this will not come to our control magnitude output. the 4-20mA output that you will get is the weight of the material only (excluding the tare). 2, if you want a rage of max 6t this you have to set in the controller (some thing like nominal capacity will there will depend on your controller). if you set max as 6t so your mill amps output also will comes accordingly. But one thing that confusing me is you tell this as conveyor so this is not static so speed of the conveyor is also come to action.....its not clear whether ur measuring the feedrate or static value.....

Dear Guess,.

Yes sure, there is conveyor and load cell is put on the conveyor's frame. we will control the conveyor (using PLC), when there is a raw material, conveyor stop(a few seconds), then weighging value is recorded to PC, after that conveyor run again, and the next raw material comes again.

There are possibilities to make CONTINUOUS measurements without conveyor stop. You can put on cells only a part of the conveyor ( at least 3 rollers) in a frame which can move with respect to the rest of the conveyor structure. Results can be very accurate but have no commercial value, only for internal use. The distance between rollers has to be such that the transport band flexion is low as stiffness and does not induce important parasitic loads.

There is no need to stop the conveyor just to measure the raw materials on top of the conveyor. you can measure it while the conveyor is running continuously. installing 4-6 idlers with correct position and weigh frame. you can use two load cells put under the weigh frame. there is also a tachometer installed at the tail pulley to measure the length of the conveyor that passes through the weigh frame in terms of pulses. the signal from two load cells and tachometer will be fed to the integrator and compute so as to get the material flow rate info, belt speed and total accumulated material being transfered. calibration is the big factor in order this weighing system will perform more accurate. tachometer calibration, zero and span calibration.. try explore this link http://www.controlsystems.com.au/

Thank You everyone,..

my project is successfully complete.

my client is satisfy. although there is a little problem in mechanic. but it will be homework for them for next same project. to improve their mechanic construction.

Thank You for your helping